nums =[1,2,3]
//获取数组中迭代器
nums_iterator = nums[Symbol.iterator]();

val1 = nums_iterator.next()
console.log('val1=',val1)

val2 = nums_iterator.next()
console.log('val2=',val2)


val3 = nums_iterator.next()
console.log('val3=',val3)


val4 = nums_iterator.next()
console.log('val4=',val4)

// for(const item of nums_iterator) {
//     console.log('item====',item)
// }




